


Achilles' Heel

by nostalgia



Category: Doctor Who (1963), Doctor Who (2005)
Genre: Awesome Donna Noble, Gen, half human, on his mother's side
Language: English
Status: Completed
Published: 2014-04-26
Updated: 2014-04-26
Packaged: 2018-01-20 22:07:25
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,338
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1527398
Author URL: https://archiveofourown.org/users/nostalgia/pseuds/nostalgia
Summary: <blockquote class="userstuff">
              <p>The Doctor's past is being unhappened, can he and Donna prevail before he disappears from history?</p>
            </blockquote>





	Achilles' Heel

They were laughing when it started. For the first few seconds Donna thought he'd pulled a muscle, but then he started to fall and he had to lean on the console to stay upright as his knees gave way.

She was beside him in a moment, helping to catch him as he started to fall. “What is it? What's wrong?”

He tried to speak but he couldn't, clutching at the right side of his chest and gasping for breath. He fell to the grated floor of the console room.

Donna crouched beside him. “Doctor!”

He tried to say something but he couldn't control his breathing to speak. For a moment she was fairly sure that he was dying. 

The attack ended as suddenly as it had started. Donna held him with his head on her lap as he recovered.

“What the hell was that?” asked Donna, obviously concerned.. She helped him to his feet and held on to make sure he wouldn't fall again. 

“Time,” he said when he could talk, “someone's changing my past. Rewriting my history or taking something from me.”

Donna let go of him when she realised he could stand on his own. She didn't move away though, still hovering close in case he fell again. “Are you sure? How can that happen?”

“I've felt that before,” he told her, “when my past selves were being kidnapped.” He frowned, concentrating. “Something's been erased.” 

“Is it going to happen again?” she asked. 

“That was just the first attack. It'll be back and it'll be worse.”

“How bad is it going to get?”

“Deadly,” he said, matter-of-factly. “Listen, Donna, I need you to trust me.”

“I _do_ trust you,” she said. 

“There are things I can't tell you, but I need your help to fight this. I need you to do what I tell you and don't ask any questions.”

Donna didn't hesitate. “Anything.”

He turned back to the controls, started setting the coordinates for their destination. “We'll go right to the source, no point wasting time.”

Donna stood anxiously at his side as they tumbled through the vortex.

 

They arrived in what looked to Donna like the present day. The TARDIS had materialised in the garden of a semi-detached house and Donna stepped out wondering what exactly the Doctor hoped to find that would be able to help them here.

He exited the TARDIS and said, “You wait here.”

Donna shook her head. “No,” she said, “I'm not letting you wander off on your own.” She was far too worried about him to let him out of her sight.

He looked at her for a long moment and then nodded. “Fine, but no questions.”

“Where are we?” she asked.

“What did I just say?” he countered.

Donna opened her mouth to protest, reconsidered, and followed him silently up to the door of the house. The Doctor rang the doorbell, waited for about thirty seconds, then let himself in with a key.

_He has a key?_ she thought to herself. Something weird was going on here and she didn't like it one bit. She entered the house after him, almost tripping over a ginger cat that tried to wrap itself round her legs.

“Mind the cats,” he said belatedly.

Donna looked around. It seemed to be a normal suburban home. She walked over to the fireplace, examined what looked to be a collection of snowglobes. She wondered if she wasn't supposed to touch anything, like at a crime scene on TV, then shrugged and picked up an ornament with Edinburgh Castle in it. She shook it and a blizzard enveloped the city. 

“It's empty,” said the Doctor, from the doorway. “No one here. I checked all the rooms.” He shooed away a large black cat and walked over to her, took the snowglobe from her hand and replaced it where she'd found it. 

“Maybe whoever it is went out,” she suggested.

“No,” he said, “there's a cup of tea in the kitchen, still warm.”

“What about the cats?” she asked, because surely he hadn't meant _any_ sort of question. 

He frowned at her, confused. “What about them?”

“Shouldn't we at least put some food out for them?”

“Oh.” He shook his head. “They won't be here for long.” He headed out of the room. “Come on, no point wasting time here.”

Donna followed him out, completely perplexed. One minute he was dying and the next he was breaking into people's houses. True, he was a weirdo, but even for him there were limits.

 

The next stop was the same house, but the air was warmer and the garden was in bloom. He still hadn't told her what was going on, but she followed him back up the garden path without complaint or question. 

The Doctor rang the doorbell and waited impatiently for an answer, bouncing on his heels and trying to look through the frosted glass on the door.

Finally the door opened. A small boy of about six, with dark hair and light eyes, looked up at them warily.

“Hello,” said the Doctor, “is your mum in?”

“I don't know where she is. Are you a policeman?” asked the boy, looking past them to the TARDIS parked by the garden gate.

“Sort of,” said the Doctor. “Can we come in?”

“I'm not supposed to talk to strangers.”

“We're not strangers,” said the Doctor. “Me and your mum go way back.”

Donna looked at him, thinking fast. Were they looking for a girlfriend? Did he he have an evil girlfriend who was making him sick? Was this his kid?

The boy let them into the house and the Doctor did a quick tour of the ground floor before heading for the staircase in the hall. 

“Donna, I'm going to look upstairs, you stay down here. Don't let him out of your sight,” he said, pointing at the little boy.

Donna sat down on the sofa in the living-room. “What's your name?” she asked, trying to seem friendly and not threatening. She noticed that the snowglobes were still on the mantelpiece, though in fewer in number now.

The boy looked at her doubtfully. “I'm not supposed to say, not to people I don't know.”

“Just your first name,” she said, pretending that wasn't in any way strange. “I have to call you something, don't I?”

“John.”

“That's a nice name,” she said. “I'm Donna. My friend's called-”

“Don't tell him,” said the Doctor, entering the room.

“He's called John too,” lied Donna, using the Doctor's usual uninspired alias. 

“I'm going to check the garden,” said not-really-John. 

Donna liked to think that she was good with children. “Is it just you? You don't have any brothers or sisters?”

He shook his head. 

“Well,” said Donna, and then suddenly she was alone. She stood up, looked around. He couldn't have gone anywhere, she'd kept her eyes on him as the Doctor had to told her.

“Doctor!” she ran out of the room, bumped into him in the kitchen. “He's gone,” she said. “He just... he's gone.”

The Doctor didn't ask what she meant. “It's happening faster than I expected,” he said, pale. Suddenly he dropped to his knees, breathless. 

Donna knelt down beside him. “Doctor, what do I do?”

He shook his head, face contorted in pain. He grabbed hold of her hand as though afraid that he might vanish too. 

Donna pulled him against her, holding him until the second attack stopped. 

 

Back in the TARDIS the Doctor set the coordinates again. Donna glanced over his shoulder, read _1963_ on the little screen that showed the date, retreated into thought.

He'd said not to ask any questions, and she'd agreed to that, but she was also worried and she was starting to piece things together.

“That little boy,” she said. “He was you.”

The Doctor glanced at her and shook his head. “Don't be ridiculous. How could he be me? I'm from another planet.”

“Yeah, but,” she pressed on, “you said something was erasing your past. And then he wasn't there any more and you got sick again.”

“Coincidence.”

Donna fisted her hands in frustration. “Doctor, I'm not stupid.”

He turned to look at her, really look at her. “No,” he said, “you're the opposite of stupid.” He sighed. “Why do I always pick the clever ones?” he asked himself. 

“How can that kid be you? What happened to him? Where did he go?” She had something of a backlog of questions to get through. 

“He didn't go anywhere, Donna. He was never born.”

“If you weren't born, why am I talking to you?”

“It's like,” he searched for an appropriate simile, “it's like pulling at a thread and until your jumper unravels. It doesn't happen all at once.”

“But...”

“Time doesn't like making sweeping changes all at once,” he told her. “And I'm a Time Lord, so I'm not as vulnerable as you'd be.”

“A Time Lord who was a little boy on Earth?” She was a bit confused on that point.

“I'm sort of... my mother... that is...”

“She was human,” said Donna, working it out. That did seem to explain quite a lot.

“Yeah.” He shrugged. “My dad took me to Gallifrey when I was eight, to start school, I never went back to Earth until I was an adult.” He flicked a few switches on the console, distractedly. 

“Wow,” said the Donna. “Any other stunning revelations you've been hiding from me?”

“Well, yes,” said the Doctor, “but I'd like to keep _some_ secrets, if you don't mind.”

Donna's brain seemed to be working overtime just to catch up on everything. “You really are called John Smith? That's actually your real name?”

“No. Well, yeah. Depends what you mean by real name.” He shrugged. “Look,” he said, “I thought I'd use an alias that was easy to remember. Something that didn't really seem plausible for an alien.” The TARDIS shuddered to a halt. “Right,” he said, eager to get off that topic, “next stop.”

 

 

It was the same house, again, but the trees had lost their leaves and the sky was dark. The Doctor stopped Donna just before they reached the door. “Listen, if she's here, you don't say anything to her about the future, or about me.”

“Yeah, still not stupid.”

He nodded and rang the doorbell. 

It was answered by a red-haired woman in her mid-twenties. She was holding a baby. “Can I help you?”

The Doctor flashed the psychic paper at her. “Immigration, we'd like to have a word about your husband. He's been reported as an illegal alien.”

Donna thought that was a bit much, so she added, “It's probably just a neighbour with a grudge, nothing to worry about. Can we come in?”

The woman stared at her for a moment and then nodded. “He's not here, though. He's away on business.”

The snowglobes were gone now, and the house looked a bit less cluttered overall. 

“Well,” said the Doctor, “Mrs Smith...”

“Susan, please.”

“Susan,” said Donna, “can you think of anyone who doesn't like you?”

She looked at Donna oddly. “I keep myself to myself.” Her baby started to cry. “It's time for his feed,” she said. “Could you?”

Donna took the offered infant and Susan went to the kitchen. It was a bit weird, holding the Doctor as a baby when he was standing next to her as an adult. Weirder than she was used to, which was pretty weird generally. 

“He doesn't look much like you,” she whispered to the Doctor. 

“He looks like Winston Churchill,” said the Doctor, “All babies do at that age.”

“Yeah, but -”

“What did you expect? Sideburns and tiny pair of Converse trainers?”

“I dunno,” she said, “I didn't really think about it.”

Susan reappeared with a bottle of milk and took her son from Donna. “Thanks,” she said. She sat on the sofa to feed him. “I have to be honest with you,” she said, “I haven't seen my husband for some time.”

“Can I ask where you met him?” asked the Doctor. “The place and the exact date.”

“Why?”

“Just for our records,” said the Doctor. 

Susan looked at them with obvious suspicion. “I'm afraid I can't tell you that. He's a very private person.”

“Must run in the family,” muttered Donna, and the Doctor nudged her with his elbow. 

“Can I see your identification again?” asked Susan. 

“We're only allowed to show it once,” said the Doctor. “For... reasons.”

She stood up suddenly. “I'm going to have to ask you to leave.”

Donna tried to allay her suspicions. “We've got your best interests in mind.”

“Even so.”

The Doctor nodded. “Yeah,” he said, “probably best we were off now.”

Susan saw them out and Donna looked at the Doctor. “We're just giving up?”

“She's obviously fine _now_ , and the baby seemed healthy enough. We need to go back a bit further.”

 

The Doctor was worryingly good at stalking people, as it turned out. He found Susan Smith again easily enough, at any rate. 

They followed her down the street trying not to attract attention. 

“Who'd want to kill you before you were born?” asked Donna, then realised that could be any number of people. “Do you know who it is?”

The Doctor shook his head. “We'll deal with that problem when we get to it.”

The woman in front of them stopped suddenly and turned to look at them. Her hair was tied back and she was obviously pregnant. 

The Doctor and Donna stopped walking and attempted to look innocent. The Doctor bent to pretend to tie his shoelaces. 

Susan approached them, anger on her face. “Why are you following me?” she demanded.

“We're not,” protested Donna. “We're just walking down the street.”

“Who are you? What do you want?”

Donna wondered if they should just tell the truth, but the Doctor was used to lying all the time. “We're just normal people walking down the street.” He pointed at a house. “That's our house over there.”

“That's Mrs Goldstein's house,” said Susan. 

“We're her... children?”

“You don't look anything alike.”

“Fraternal twins,” said the Doctor. 

“You don't look like her either.”

“We take after our father,” he insisted.

Suddenly Susan fell forwards. The Doctor caught her as she fell, lowering her to the ground gently. “She's been shot! Some kind of energy weapon!”

Donna looked around, ducking behind a post box in case anyone wanted her dead too. “I don't see anyone!”

Susan looked up at the Doctor. “What...”

“Hold on,” he told her, “you're going to be fine.” Donna wasn't convinced. 

Susan coughed up blood and Donna crouched down next to them. “Doctor,” she said, “we have to get her to a hospital.”

He shook his head. “She's got an alien in her womb, what do you think they'll do to her?”

Donna wasn't about to give up. “The TARDIS, then.”

He looked up, utterly lost. “I don't think I can save her.”

“You've got to! If you don't then you can't be here talking to me in the first place!” 

“I know that!” He looked down at the woman in his arms. “This isn't supposed to be happening,” he told her. “Trust me when I say you're supposed to live to a ripe old age.”

Susan closed her eyes, and didn't open them again.

 

They raced back to the TARDIS without her. 

“If we're lucky,” said the Doctor, “we should time for one more go.” He moved around the console quickly, pressing buttons and turning dials.

“What do you mean 'if we're lucky'?” demanded Donna. 

“Donna, my mother's just died before I was born. My entire life's being unwritten.” He closed his eyes for a moment, looking pained.

Donna looked at him. “It hurts,” she said, realising. 

He glanced at her. “It's only pain. I'm no use to her if I don't find a way save her.”

“But -”

“Donna! Focus!” The TARDIS landed and he ran to the outer doors. “We've gone back ten minutes, that should be enough.”

They were on the other side of the street now. The Doctor pulled the sonic screwdriver from his pocket and scanned the area. “Someone's using a perception filter, but it's not a very good one. Look for something that's wrong, anything that doesn't look right.”

Donna looked around. “That tree,” she said, pointing, “it's not moving with the wind.”

They ran across the street. The Doctor did something with the screwdriver and the tree flickered. Donna saw an alien in it's place, green with two sets of eyes. Between them they wrestled it to the ground, trying to take the gun from it's slimy grip. 

“Who are you?” demanded the Doctor as Donna struggled to get hold of the weapon.

The green alien glared at him. “Don't you recognise me?”

“Should I?”

“You've meddled for the last time, Doctor, I know your secrets. I know how vulnerable you are, here in your past.”

“Yeah,” said Donna, getting hold of the gun, “but who are you?” She sat back on the pavement, short of breath from the struggle. 

“You really don't know who I am?”

“Haven't the slightest idea,” said the Doctor. 

The alien stared at him for a moment, then reached to touch something on its wrist.

“No you don't!” cried the Doctor, moving to stop him. 

The alien vanished from under them. The Doctor swore. 

“Have we stopped him?” asked Donna. 

“I doubt it,” said the Doctor. He looked at her, distressed. “He can come back at any time. Over and over again until it sticks.”

“So we'll stop him again,” said Donna, even though she could see the obvious flaw in this idea.

“What, we spend the rest of our lives following my mother about in case someone kills her again?”

“There must be something we can do!” she insisted. 

The Doctor looked pained. “Yeah,” he said, “there is.”

 

They watched from a distance as Susan made her way home from the shops.

“You're sure she'll be safe now?” asked Donna. 

“I don't feel anything missing from my past,” he told her, “so we probably assume that it's worked. The barrier should keep out whoever was trying to kill her.”

“And you,” said Donna, pointedly. 

He shrugged. “I created a series of fixed points, the TARDIS doesn't like those. She gets cranky when she has to cross her own timeline.” 

She touched his arm. “I know I can't make it better, but I'm sorry you had to do it.” She thought for a moment. “Doesn't _this_ change your past? Like, how do you have a key to the house if you can't go near her?”

“Artefacts,” he said. “There's always something left over when time gets rewritten.”

“She can never see you again, either,” said Donna. “That doesn't seem right. Hang on.” She took her phone from her pocket, aimed it at the Doctor, and snapped a photo. Before he could stop her she crossed the street and walked along until she was alongside Susan. 

“Listen,” she said to her, “I know this doesn't make any sense, but I want you to have this.” She handed over her phone. “Um, you probably won't be able to work it for a while, but it's worth holding on to.”

Susan stared at her, baffled. “Do I know you?”

“I'm a friend of the family,” said Donna. “And don't worry about your kid, he'll be fine.” She paused. “Maybe you could tell him not to lie so much to his friends, though.”

 

When she got back to the Doctor she said. “Okay, let's go.”

“Donna, you just contaminated the past! You gave someone a mobile phone in 1963!”

“Shut up,” she told him.

“You can't just do things like that!” he protested. “Time's a very sensitive thing!”

“Yeah,” she said, “I've noticed.”

He shoved his hands into his pockets. “Well,” he said, “I hope you don't do it again.”

“Guide's honour,” she said. She took his hand. “Let's go home,” she said. “Let's go back to the TARDIS.”


End file.
